Fire Rebirth
by Blackbird0
Summary: Fire Lord Zuko has accomplished more than most men would dare to dream of doing in his lifetime. He has stumbled and fallen more than any other person, but he has never stayed down for long. Zuko proves to be just as stubborn in death as he is in life when he is reborn as none other than Itachi Uchiha, heir of the Uchiha Clan.
1. Chapter 1

Zuko, The Banished Prince, The Traitor Prince, the Avatar's fire bending teacher and the 37th Fire Lord had ruled for 46 years before retiring and passing the throne to his daughter. He had sailed from one end of the world to the other, crossed continents, and seen legendary creatures and spirits. Zuko had survived countless assassination attempts on his person, the first when he was ten years old by his own grandfather, to the numerous he'd thwarted after taking the throne. He had quelled a civil war in his country before it started and helped reunite a world of people after a hundred year war.

Zuko had many regrets - he'd made more mistakes than he could remember. But even so, he was happy with the way his life had turned out. His mistakes made him who he was, and if given the choice, he wouldn't change any of it. Well… maybe he would make a couple of changes. Some of the things he did were monumentally stupid.

But that aside, Zuko was content as he lay in his bed, feeling his inner fire slowly fade. He was at peace with himself and was looking forward to seeing old friends and his uncle in the spirit world. And so, surrounded by his children and grandchildren, Fire Lord Zuko passed away.

But the end is never really the end. Time keeps ticking and life continues on. For Zuko, the universe wasn't ready to let him go so easily. He and Sokka had an on-going competition for the title 'most hated by the universe' - they never did agree in the end.

And so the first feeling Zuko had when he was reborn into the time of the bloodiest war in shinobi history as the heir of a ninja clan was vindication.

He always knew he was the universe's favourite punching bag.


	2. Chapter 2

**Disclaimer: I do not own Naruto or Avatar.**

 **Chapter 1**

June 9th in the 68th year after Konoha's founding saw a group of people gathered to witness a historic moment; the Uchiha matriarch was giving birth to the next head of the Uchiha clan. Of course to the soon-to-be father and elders waiting outside the birthing room it wasn't an 'I-am-experiencing-history-in-the-making' moment, but more of an 'oh-my-god-please-make-it-stop' moment. Fugaku Uchiha, a stern and uncompromising man to all of Konoha was a nervous wreck, flinching every time he heard a scream and praying with all his might that his lovely wife wouldn't carry out the threats he could hear her shouting in the room over.

An agonizingly long time later and a new scream rang through the warm summer night. This one was a welcome sound and very different from the woman's screams before; it was the wail of new-born babe. Fugaku dashed into the birthing room on shaky legs, suddenly breathless with anticipation. He was greeted with the sight of his exhausted but glowing wife laying on a bed, and in her arms was the long-awaited Uchiha heir.

"A boy." Fugaku breathed, reaching for the bundle.

Mikoto smiled up at her husband and passed over her son to his father. Fugaku took the bundle and gazed down on his son for the first time. He was taken aback when he saw the baby staring straight back at him with comprehension in his dark eyes.

* * *

Zuko was not amused.

He had died. Of that he was sure. So why was he waking up to find a gigantic man standing over him?

He had said his goodbyes to his family and had prepared himself for the judgement he would face in the spirit world - he was also pretty sure it wasn't going to be favourable since he may have pissed off more than one spirit in his youth.

Perhaps this was some sort of obscure punishment? Zuko took a look at his surroundings, finding himself in a wooden room with a lot of dark haired people in it who all had the distinct look of the people of fire. He could feel their inner flames and concluded that he was still in the fire nation. He was normally not one to swear, but... what the hell? Had the royal family hired a doctor and prolonged his life?

As he was puzzling over what the odd red and white symbol painted on the walls could mean, he heard the man hovering over him speak:

"A boy."

…

What? Of course he was male. The whole world knew who he was, and in his entire life no one had ever questioned his gender. His sanity – sure. But never his gender. Zuko squinted at the man to get a closer look. Was he … mentally retarded? Perhaps he had a condition?

It was that moment he decided he had done enough observing and it was about time he established control of the situation.

"May I enquire as to what has happened?" Zuko asked in his 'Fire-Lord-voice', as dubbed by Aang. At least, that's what he meant to say - what came out was a load of jumbled noises that couldn't even qualify as verbal diarrhoea.

The stern man smiled at him and lifted – _lifted?_ – him so the elderly people could see better.

"His name will be Uchiha Itachi, and he will surely bring honour and pride to our clan."

 _Honour_ again? ... Hold on a minute.

Call Zuko slow, but this was the moment when things finally clicked. He had been reborn! But wait, didn't that only happen to the Avatar?

…

Apparently not. Zuko shrugged – or he would have if he could control his shoulders – and rolled with it. In his long life, he had eventually learned to not take everything so seriously or else he no doubt would have died decades earlier from the stress. It was Katara's advice to 'just go with the flow', and after a decade of acting as the Gaang's voice of pessimism – he would argue realism – he had finally given up and just went along with all the crazy situations he was pulled into. The fact that he inadvertently started a not-so-insignificant number of those incidents may have had something to do with it.

Zuko was brought out of his thoughts as he felt something touch his nose. The blanket wrapping his tiny body – _his baby body!_ – was tickling his nose.

"Choo!"

Zuko let out a massive sneeze that made him use all the pitiful muscles in his body. He felt his inner fire flare out of control, causing him to notice that he no longer had as much and it was behaving as wildly as it did in his youth. As a result, all the candles in the room flared a foot high and burned red before returning to normal.

Damn, he had lost all semblance of control over his bending abilities and now he would be stuck meditating for ages until he could actually use it safely. The man – his new father he guessed – was staring at him like he was an alien. So were all the elders, now that he cared to pay attention to them.

"Did you see that?" One of them exclaimed, excitement in his voice.

"The fire! Fugaku, do you know what this means? Amaterasu has blessed him! Truly, he will one day be the greatest Uchiha to live!"

Fugaku stared down at him with awe in his eyes.

"Yes, you're right. Uchiha Itachi will lead our clan to greatness!"

Oh Agni. Please no. His new family were … part of a cult!?

He always knew that his karma would catch up to him one day, but this was taking it a bit too far - even for Zuko. He _knew_ he shouldn't have hidden Sokka's boomerang from him. Or 'accidently' burned Aang's staff that time when he became too annoying. Perhaps it was because he had set those fan-boys on Katara?

… In hindsight, Zuko probably should have anticipated something like this.

But damn, that didn't mean he was happy about it.

* * *

 **Hehe, a new chapter! I apologise for the delay, I didn't expect so many of you to like this story and I was caught up in writing my other story 'Nightshade'.**

 **A lot of people seemed to like the prologue, so I've decided to continue writing. I can't promise regular updates, but I do promise to write more when I can, so you can be sure that I'll update in the future.**

 **Please tell me what you think :)**

 **Blackbird0~**


	3. Chapter 3

**Chapter 2**

To Zuko's great relief, his new family were not part of a cult. Instead they seemed to be rather normal people – they were well-mannered, cultured, fire breathing people who were very assured of their own superiority and had a family history of insanity.

Zuko had never felt more at home.

His new mother was a gentle woman, much like the Princess Ursa had been. She obviously loved him very much and while it felt weird to be cared for after years of taking care of himself like the adult he was, Zuko found himself hesitantly enjoying a mother's unconditional love.

He could do without the breast feeding though. That's was just…. No.

They also had an obsession with training all the time, just like his old family. Zuko thought they really couldn't have gotten a closer copy to his old childhood even if they tried.

There were some differences though, one of which was his new father actually liked him and hadn't tried killing him. Or at least he hadn't yet, but Zuko wasn't going to hold his breath on that lasting. It's just how his luck worked.

He was also an only child this time! His second birthday passed with Zuko spending that year in suspenseful trepidation. And then his third went by and still no sibling. His fourth and now his fifth and Zuko couldn't be happier! He spent his years exploring the compound, getting into places he had no right to be, setting his incompetent tutors who knew nothing of fire manipulation ablaze with his 'magnificent hand-seal free' fire, and generally drove everyone up the wall with his wonderfully mischievous cousin Shisui. Life as an only child was fantastic!

It was a warm winter day that saw Zuko heading back to the Clan leader's house after a productive time of attempting to get past the mysterious and fascinating chakra seals on the archives.

"I'm home!" He called cheerfully, shucking his sandals off and putting on his slippers.

"Welcome back Itachi!" Mikoto greeted him from the kitchen, the smell of her excellent cooking drifting through to tickle and tantalize his nose. "Would you set the table dear?"

"Of course."

Another thing was the lack of servants, but that was fine. It turns out that the people he lived with were just as paranoid as he was, and nobody trusted servants not to poison them. Fugaku came back not five minutes later as Zuko was finishing setting the chopsticks. Soon enough the small family settled down to eat.

However, just as Zuko was about to dig in, Mikoto spoke up:

"We have wonderful news Itachi. You're going to be a big brother!"

Fugaku and Mikoto beamed at him, their happiness lighting up their faces. Well, Mikoto looked overjoyed. Fugaku looked less constipated than usual, so Zuko assumed he was happy.

Zuko, meanwhile, felt all his previous joy and contentment vanish, and his soul shrivel and die.


	4. Chapter 4

**Chapter 3**

Zuko eyed the small lump with distaste, staring at the being before him. It was filled with malevolence and spite, a harbinger of chaos and destruction, and would most certainly try to kill him at some point.

"I know what you are." Zuko said solemnly, seriously.

Dark eyes blinked innocently back, set on a chubby face with a healthy rosy glow.

"You won't fool me. I'm too canny for that. It's simply impossible for me to have a normal sibling. Impossible! You're going to grow up to be a fire-breathing psychopath, become crazy and obsessed with hunting me down, and then devote your life to killing me for being a disgrace to the family. It's inevitable."

 _Just like Azula._ Zuko thought but didn't say.

"Itachi!" Mikoto scolded. "I know you weren't happy with a sibling, but you shouldn't say that to your baby brother. You're usually so mature, I don't know what's gotten into you!"

"But mother!" He protested at the unfairness. "Look at him!"

Zuko brandished baby Sasuke's adorably chubby face at Mikoto.

"Can't you see his innate evil?"

Both Mikoto and Fugaku paused their chopsticks over their breakfast and stared at him incredulously. Sasuke took the moment to start burbling.

"Ub bub bub bub."

Zuko's new parents laughed and Mikoto lifted his younger sibling out of his hands and cradled him closely.

"Aren't you adorable!" She cooed over him, wiggling her fingers at the baby.

The Fire Lord reborn gazed at his parents in horror, before shaking his head and heading for his sandals.

"I'm going to find Shisui!" He called back and left swiftly before he had to endure the insanity further.

That morning, the Uchiha heir could be found ranting to his cousin and best friend about the evils of younger siblings, and how his brother had only existed for a month and had already conned his parents into thinking he was harmless.

"You should see them Shisui! It's sickening how easily they fell for his act. Just this morning as I was trying to enlighten them, and after I revealed his true nature, he starts doing this adorable baby talk. A coincidence? I think not! The timing was way too perfect, I know it's all an act, it must be!"

Zuko paused and gasped in a huge breath, but before he could continue was halted at the sound of Shisui's snickering, which swiftly devolved into rib-cracking howls of laughter.

"Ahahaha! Ow, my ribs! Itachi I can't take it anymore, ahahahaha!"

"I don't know what you find so amusing, cousin." Zuko spoke with gritted teeth and a threatening undertone. "This is a serious situation; I have a demon masquerading as my younger sibling! He'll grow up and when everyone sees his true self, it'll be too late!"

Shisui controlled his laughter with a great exertion of will.

"Itachi." He broke off to snicker some more before clearing his throat. "Just give it some time, you'll warm up to him I'm sure."

Zuko rolled his eyes. "Not bloody likely." He muttered under his breath.

The days slid by and Zuko simmered in watchful paranoia, waiting for a sign that would prove his suspicions correct. He didn't have to wait long.

It was October, and his parents were out and had left him to mind the spawn, when an ominous atmosphere descended upon the village. Like the world was holding its breath, the air stilled and the more sensitive people tensed, waiting for … something. Then there was an explosion and Zuko could see a massive red beast roaring and whipping appendages around wildly.

He spent some time gaping before he shot to his feet, whipping his head around to look at the crying bundle that was Sasuke. He picked him up, but before he could move further one of his clansmen barged in, shouting:

"Itachi-sama, you must hurry to the shelters!"

Zuko nodded already moving past him. The rush of panicked people streaming toward the mountain was huge, and the sheer terror in the air was thick enough to choke on. The toxic feeling of the demon on the horizon compounded things, making it difficult to even breathe.

The shelters were full of crying people and terrified civilians, all huddled together desperate and shaking.

"What… what was that?" One of the kids spoke timidly, the question hanging in the air.

"It's a demon." Zuko responded grimly, looking down at Sasuke who hadn't stopped crying.

 _And it's come for its progeny._


	5. Chapter 5

**Chapter 4**

Even though the Kyuubi had only been inside the village for less than a minute before the Fourth Hokage teleported it away, the death toll was a huge ten percent of Konoha's population. Every person knew someone who had died, and the grief lingered heavily in the wake of the attack.

Regardless of the losses, the clean-up of the devastation proceeded at a swift pace. An interrogation of Mikoto when she finally arrived home and had a few minutes to spare, yielded the information that these demons were actually malevolent spirits that were sealed into people, and that the seals can sometimes malfunction. Without an Avatar to pacify the spirit, Zuko supposed sealing them was the best option they had. He was rather glad that he hadn't voiced his thoughts on why the demon had appeared, as he admittedly may have – only slightly! – overreacted.

Despite of the exhaustion the work caused all people in the village, Zuko was highly impressed with the efficiency of the operation, and it wasn't long before key areas of the village were back in working order. Areas which, unfortunately, included the academy.

The academy was a special kind of torture with the class slowly slogging through a curriculum meant for young children that his over-enthusiastic clan had already taught him. Zuko felt he displayed great patience by lasting a whole week, before caving and sending a shadow clone to attend for him.

He was still attending! His spotless attendance record would attest to it. He was just - also not.

Instead, the reborn Fire Lord spent his days working through his fire bending kata and creating lightning – a different thing from lightning release.

Bending didn't seem to exist in this world, likely because these people had weaponised chakra instead. Zuko vaguely recalled being told by Aang that unblocking his chakras had involved 'cryptic riddles, a lot of meditating, and too much onion and banana juice'.

In Zuko's opinion even just the thought ofonion and banana juice was too much, but who was he to question the expert?

The chakras Aang spoke of were the nexus points of chi flow, which is how bending works. The chakra they use here is another energy altogether with its own circulatory system; a system that seems to prevent a person's chi from instinctively reaching out to its element, which is why temper tantrums here didn't result in cracked icebergs and drowned Sokkas.

Zuko was a fire bender and always would be; his chi would connect with nothing else. But now he had the power to mimic the bending that he had seen preformed using chakra. He was very keen to try some of Katara's water bending dances, Aang's evasive air bending style and Toph's frankly terrifying earth bending.

Aang was the Avatar, and consequently a monster of a bender to fight. Katara was terrifying as a person, and her bending only augmented her fright-factor. And while Zuko would unabashedly admit to being thoroughly intimidated by Katara, it was Toph's bending that Zuko felt was the most threatening.

Most earth benders were straight forward; they attacked with the earth, they defended with the earth. It was a tool to be used, a weapon to be wielded. Toph however, was frighteningly adaptive and she moved the earth like it was simply another one of her limbs. She didn't attack or defend, there was no line between them to her. She simply moved, and the earth moved with her.

Zuko planned to work through the elements in the order of the avatar style, and so was in the process of learning to cut a leaf. It was extremely tedious and explained why people simply learned handsign combinations instead of going through elemental manipulation training, but Zuko wanted to learn it properly and anticipated years of work before him. So while he diligently practiced it every day, he took breaks in which he got his fire bending back up to the standard it was before he died.

The winter sun was weakly shining down on Zuko as he stood in the middle of his favourite training ground located on the edge of the Uchiha complex. He sucked in a deep breath before releasing it slowly; green, purple, and red mixed in with the regular yellow-orange flames leaving his mouth, swirling up in front of him and coalescing into the form of a dragon. He flicked his wrist, a thin streak of flame whipping out and connecting to the head of his creation, and he guided it to fly around him. Another exhale and a second dragon appeared, this one joining in the dance joyfully, like a reunion of old friends.

Memories of the Dancing Dragon he and Aang learned at the Sun Temple flickered through his mind and he could almost smell the fresh mountain air, hear the crackle of the Sun Warriors' flames, and the flap of the dragons' wings as they flew higher and spun around them in dizzying circles.

Zuko flowed through the steps of the ancient fire bending form smoothly, the dragons he'd created moving in sync until they reached the climax of the dance and they crashed together, dissolving back into formless flames around him before extinguishing.

Eyes opening and memories fading back to the depths of his mind, Zuko straightened and turned to the person who had arrived stealthily and was crouching on a tree.

"Shisui."

The perpetually cheerful Uchiha hopped down, landed silently, shaking his head and whistling.

"Damn Itachi! That's some serious fire style you've got going there!"

Zuko quirked a smile. "It's actually a two-person kata I was preforming. It's not quite the same with one person." He tilted his head in contemplation. "Want to learn?"

His cousin was undoubtedly capable of fire bending, as evidenced by the classic Uchiha tendency for being pyromaniacs of the highest degree.

The best people were, in Zuko's - completely unbiased - opinion.

Shisui bounced excitedly on his feet.

"Hell yeah! But I heard you already tried explaining it to the elders and no one could get it."

Zuko could feel his face scrunch up in irritation at the reminder and waved his hand dismissively.

"They're all old and stuck in their ways. No one really tried to understand. I'm sure you can get it though."

"Hah!" His cousin barked, grinning. "I'd better, or else I'll be the same as those crusty crustaceans, and that's just impossible!"

Shisui's cheer was infectious and Zuko grinned as well.

"Right then, step one. Forget everything you've ever learnt about fire manipulation."

Shisui nodded and straightened his posture, focusing on him with an intense gaze, all traces of his joking demeanour gone. He was already doing better than every Uchiha elder, Zuko thought wryly. So assured of their own knowledge even when faced with evidence that there was another way to do things.

"What is fire? At its core, what is it?"

Shisui thought for a moment. "Combustion?"

"Not quite. You're thinking of how it appears and what it does. What is it at its most basic?"

His eyebrows scrunched together. "Its… heat and light, I suppose."

"Yes. And both are forms of energy." Zuko nodded. "Essentially, fire is the elemental expression of energy. There is energy all around us, and just as nature takes this energy from the sun and repurposes it, we can too. Because we are alive, we also have energy within us. Fire bending is the art of understanding the connection between the fire within and the fire outside. Learning to move your inner energy will allow you guide any flame, any form of heat, whether you create it or not."

Messy black hair bobbed as Shisui nodded in fascination.

"So how do I start?"

Zuko's lip quirked as he remembered his uncle's endless lectures on the topic.

"You start with breathing."

"Right." Shisui took a stance and immediately breathed deeply while Zuko pouted at the complete disparity in Shisui's behaviour and his own at that age.

"Close your eyes, focus on the feeling of the sun on your skin. Feel the warmth heat your body, and also feel the warmth of your body heat your surroundings. Just as the sun creates energy, there is also an energy source inside you. Not your chakra, don't touch your chakra at all. It's not the humming under your veins you're trying to feel. It a gentle stream, a flow of feeling, something intangible that you feel in your mind rather than with your senses. Contemplate this energy as you breathe."

Zuko plucked a leaf out of the air as a slight breeze sighed through the trees. A tiny sizzle and a singed hole appeared in the centre of the leaf.

"Power comes from the sun, and you use your inner energy to guide it. Focus on that power as well as on this leaf." He placed the ends between Shisui's fingertips. "A small amount of energy is in this leaf, slowly burning away at it. Draw power from the sun with your inhale, and metaphorically breath life back into the smouldering edges of the leaf."

His cousin continued his slow breathing and Zuko tapped his feet with his own, so they were further apart and planted solidly on the ground.

"Sink into a stable position, yes, like that, and feel your leg muscles work and use energy as they hold you there. Feel the sun and breathe in, guide the flow through your body to your hands. Breathe out, the energy is mingling with the leaf and igniting it."

Silence fell in the clearing, leaving only the faint rustling of leaves and the sound of deep breathing. Zuko slowly worked through his kata as he waited, aiming for perfection rather than speed. The Uchiha trained their children young in fire manipulation, and while it was different from fire bending, fire bending is more instinctive and should come quickly if they know to ignore the ever-present hum of the chakra network. And sure enough –

"Itachi!" Shisui yelped and flailed, his hands brandished in Zuko's direction.

Zuko grinned and laughed joyously, utterly delighted.

"Congratulations Cousin." Zuko smiled at the look of amazement on Shisui's face as he cradled a small flame above his palms.

"You're a fire bender."


End file.
